1. Field of the Invention
The present invention relates to a flying type magnetic head wherein a reading/writing element and a protective layer are attached to the end surface at the air discharge side of a slider.
2. Discussion of Background
A flying type magnetic head is of such a type that a small flying height is obtained between the magnetic head and a magnetic disc by utilizing a dynamic pressure caused by the viscosity of air when the head is relatively moved against the magnetic disc. Generally, it is so constructed that as shown in FIG. 7, reading/writing elements are attached to the end surface 101 at the air discharge side of a slider 1 made of a ceramic body such as Al.sub.2 O.sub.3, TiC, and the reading/writing elements are covered by a protective layer 3. Reference numerals 4 designate lead wires for the reading/writing elements, which are formed on the surface of the protective layer 3.
As the slider 1, there has widely been used the so-called taper flat type slider, wherein a flying plane 103 is formed on the surface of each of rail portions 102 which project from the surface opposing to the magnetic disc with a certain distance, and a tapered portion 103a is formed at an end at the air discharge side of each of the flying planes 103 so as to produce a lifting force to the magnetic head.
The reading/writing elements 2 are respectively thin film elements formed by using the same process as the IC manufacture technology.
FIG. 8 is an enlarged cross-sectional view of a portion near the reading/writing element 2 wherein a reference 21 designates a lower magnetic layer made of a material such as permaloy, a numeral 22 designates an interlayer formed by a material such as Al.sub.2 O.sub.3, SiC and so on, a numeral 23 designates a coil conductor, numerals 25-27 designate layer insulators formed by a photoresist method, and a numeral 28 designates an upper magnetic layer made of a material such as permaloy. The protective layer 3 covers the reading/writing elements 2 and the substantially entire part of the end surface 101 of the slider 1 by sputtering a material such as Al.sub.2 O.sub.3, SiC and so on.
However, the conventional magnetic haed had problems as follows.
(a) As shown in FIG. 9, the conventional magnetic disc device was so constructed that a lead wire 5 is firmly attached to a lead conductor 4 for the reading/writing element 2 by means of soldering and so on, and an overcoating resin 7 was applied on the upper surface side 104 of the end surface 101 (which is opposite the floating plane 103, to electrically insulate and protect the jointing portion of a lead wire 5 and the lead conductor 4. In the conventional magnetic head, however, since the protective layer 3 covered the substantially entire part of the end surface 101 of the slider 1 and the edges of the protective layer 3 were flush with the edges of the end surface 101, the overcoating resin 7 flowed toward the upper surface 104 opposite the flying plane 103. When the overcoating resin 7 was solidified at the upper surface side 104, the dimensions of the outer configuration of the magnetic head changed. In order to eliminate this, it was necessary to remove the overcoating resin 71 solidified at the upper surface side 104; this reducing efficiency in the manufacture of the head.
(b) Since the protective layer 3 was formed to cover the substantially entire part of the end surface 101 of the slider 1, cracks and fragments were apt to produce in the protective layer 3 when cutting operations were carried out to thereby invite reduction in reliability and processability.
FIG. 10 shows schematically how the conventional magnetic heads are manufactured.
First of all, several groups of head pieces H.sub.1 -H.sub.n which have reading/writing elements 2 covered by the protective layer are formed on a ceramic substrate 1 as shown in FIG. 10a, then, the head piece groups H.sub.1 -H.sub.n are cut at cutting positions (X.sub.l -X.sub.l)-(X.sub.n -X.sub.n), whereby the several groups of said pieces H.sub.1 -H.sub.n n are obtained as shown in FIG. 10b.
The resulted head piece groups H.sub.1 -H.sub.n are subjected to grooving and grinding which are required to form sliders, and thereafter, each of the head piece groups is cut at cutting positions (Y.sub.l -Y.sub.l)-(Y.sub.n -Y.sub.n) to obtain individual head pieces.
As previously explained in reference to FIG. 7, the protective layer 3 is formed as a single layer on the ceramic substrate including the groups of the head pieces H.sub.1 -H.sub.n so that the magnetic heads with the protecting layer 3 covering the substantially entire part of the end surface 101 of the slider 1 can effectively be obtained. Accordingly, when the groups of head pieces are cut at the cutting positions (X.sub.l -X.sub.l)-(X.sub.n -X.sub.n) and (Y.sub.l -Y.sub.l)-(Y.sub.n -Y.sub.n), the ceramic substrate 1 and the protective layer 3 are simultaneously cut by a cutter 8 to form the individual sliders as shown in FIG. 11. However, a crack and a fragment 31 are apt to produced in the protective layer 3 since the ceramic substrate 1 is made of a material such as Al.sub.2 O.sub.3 or TiC, and the protective layer 3 is formed by sputtering a material such as Al.sub.2 O.sub.3 or SiC. This reduces processability of magnetic head.
In order to eliminate the above-mentioned problem, it was necessary to use separate cutters which are suitable to cut the protective layer 3 and the ceramic substrate 1. However, this inevitably reduces the efficiency of manufacturing the magnetic head.